A known valve timing control apparatus, disclosed in JP2004-340142A, includes fluid pressure chambers formed at one of a driving side rotational member and a driven side rotational member, and dividing portions, formed at the other one of the driving side rotational member and the driven side rotational member so as to divide the fluid pressure chambers into advanced angle chambers and retarded angle chambers. Supplying or discharging of a fluid relative to the advanced angle chambers or the retarded angle chambers is controlled, and thereby a relative rotational phase of the driven side rotational member relative to the driving side rotational member is controlled. According to JP2004-340142A, a spool valve controlling the supplying and discharging of the fluid relative to the advanced angle chambers or the retarded angle chambers, is arranged in a longitudinal direction of a camshaft so as to dispose the driving side rotational member and the driven side rotational member between the spool valve and the camshaft.
In order to improve controllability of the fluid relative to the advanced angle chambers and the retarded angle chambers, a length of the spool valve is sufficiently maintained so that an operational accuracy of the spool valve does not affect the controllability to a great extent. On the other hand, according to the valve timing control apparatus disclosed in JP2004-340142A, the spool valve is arranged in parallel with the longitudinal direction of the camshaft. Therefore, when the length of the spool valve is sufficiently maintained, a longitudinal length of the valve timing control apparatus is elongated, and mountability on an engine may be deteriorated.
A need thus exists for a valve timing control apparatus, which is not susceptible to the drawback mentioned above.